Explosion proof turbine flowmeter is a flow measurement instrument designed for use in hazardous environments. It has explosion-proof certification and can operate safely in flammable and explosive places. The explosion-proof turbine flowmeter (with explosion-proof certificate) is a new type of intelligent instrument that integrates turbine flow sensor and display developed by ultra-low power single-chip microcomputer technology. It adopts dual row LCD on-site display and has obvious advantages such as compact structure, intuitive and clear reading, high reliability, no external power interference, lightning resistance, and low cost

The difference between explosion-proof turbine flowmeter and ordinary turbine flowmeter is that explosion-proof turbine flowmeter can be directly installed in flammable and explosive environments, and has the characteristic of corrosion resistance. It can directly display the measured value of pipeline flow on site. In addition, there are many points to pay attention to during structural installation. Because explosion-proof turbine flow meters are on-site display instruments, selection needs to be based on actual parameters. Pay special attention to the usage environment of the flowmeter. The installation methods include threaded installation, flange installation, and clamping installation.

Working principle of explosion-proof liquid turbine flowmeter

When the fluid flows through the pipeline, it impacts the center turbine blade of the pipeline, generating a driving torque on the turbine, causing it to overcome friction torque and fluid resistance torque and rotate. Within a certain flow range, for a certain viscosity of the fluid medium, the rotational angular velocity of the turbine is proportional to the fluid flow velocity. Thus, the fluid velocity can be obtained by the rotational angular velocity of the turbine, and the fluid flow rate of the pipeline can be calculated. Measure the liquid in a closed pipeline, which does not corrode stainless steel 1Cr18Ni9Ti, 2Cr13, corundum Al2O3 and hard alloy, does not contain impurities such as fibers and particles, and has a kinematic viscosity of less than 5 × 10-6m2/s at operating temperature. For liquids with a kinematic viscosity greater than 5 × 10-6m2/s, flow meters can be calibrated for use.
The explosion-proof turbine flow sensor is paired with a display instrument to form a turbine flow meter. This sensor has the characteristics of high accuracy, good repeatability, and simple operation. It can be widely used in industries such as petroleum, chemical, metallurgy, and papermaking to measure the volume, instantaneous flow rate, and total volume of liquids.

Product features of explosion-proof turbine flowmeter

1. High precision: Explosion proof turbine flow meters usually have high precision, small measurement errors, and can meet various high-precision measurement needs.
2. Explosion proof design: Special explosion-proof design is adopted, including explosion-proof shell, fire isolation, and anti-static measures, to ensure safe operation in hazardous environments.
3. Multiple output modes: Provides multiple output modes, such as pulse output, 4-20mA current output, etc., which are convenient for use with various control systems and display instruments.
4. Compact structure: The structural design is compact, lightweight, and easy to install and maintain.
5. Corrosion resistance: Made of high-quality stainless steel material, it has excellent corrosion resistance and is suitable for measuring various corrosive media.

Technical parameters of explosion-proof liquid turbine flowmeter

property	Technical parameter
Instrument caliber and connection mode（mm）	4, 6, 10, 15, 20, 25, 32, 40 threaded connection (15, 20, 25, 32, 40)50, 65, 80, 100, 125, 150, 200 flange connection
accuracy level	+1%R、+0.5%R、+0.2%R(Require special order)
Range ratio	1:10;1:15:1:20
Instrument material	304Stainless steel、316(L)Stainless steel
Temperature of the measured medium	-20~+120℃
Environmental condition	Temperature -10~+55℃, relative humidity 5%~90%, atmospheric pressure 86~106Kpa
Output signal	Sensor: Pulse frequency signal, low level <0.8V High level ≥8V Transmitter: two-wire system 4~20mADC current signal
Power supply	Sensor :+12VDC, +24VDC(optional) Transmitter :+24VDC Field display type: The meter comes with 3.2V lithium battery
Signal transmission line	STVPV3x03(three-wire system), 2×0.3(two-wire system)
Transmission distance	<1000m
Signal line interface	Basic type: Hausmann connector, explosion-proof type: internal thread M20x1.5
Explosion-proof class	Basic type: non-explosion-proof products, explosion-proof type :ExduBT6
Class of protection	IP65

Selection of liquid turbine flowmeter:

1. Suitable fluids for measurement: Liquid turbine flow sensors are suitable for measuring clean (or essentially clean) low viscosity single-phase fluids (gases or liquids), such as water, light oil, petroleum solvents, acids, bases, liquid oxygen, liquid nitrogen, liquid hydrogen, etc. If measuring high viscosity liquids, the impact of viscosity on sensor performance will reduce measurement accuracy. If measuring liquids mixed with solid particles, liquid turbine flow meters are not suitable for use due to their susceptibility to bearing damage. When measuring highly corrosive liquids, it will cause difficulties in selecting materials for major components such as impellers, and their corrosion resistance has certain limitations, so careful selection is necessary.
2. Selection of caliber: Each caliber sensor has a certain flow measurement range. The selection of sensor aperture is generally determined by the flow range, that is, the small flow rate during use should not be lower than the small flow rate allowed to be measured by the aperture, and the large flow rate during use should not be higher than the large flow rate allowed to be measured by the aperture. From the perspectives of measurement accuracy and service life, it is generally believed that in situations of intermittent use (operating for less than 8 hours per day), the sensor aperture should be selected at 1.3 times the actual high flow rate during use. For continuous use (actual operation for more than 8 hours per day), the sensor aperture should be selected at 1.4 times the actual high flow rate during use. As for use under harsh working conditions (such as easily vaporized liquids, liquids containing small particles, etc.), the maximum flow rate during use should be 40% of the allowable maximum flow rate for that caliber. If the diameter of the sensor is not consistent with the diameter of the process pipeline, the pipeline should be modified with a reducing pipe and an equal diameter straight pipe. In general, the error near the lower limit of the sensor flow range is slightly larger. Usually, 0.8 times the actual small flow rate is selected as the lower limit of the sensor flow range, and a certain margin is ensured.
3. Bearing selection: In order to improve the measurement accuracy of the transmitter, efforts are made to minimize the friction torque between the shaft and the bearing. General rolling bearings are used for measuring fluids with good lubricity (such as gasoline, kerosene, etc.); Sliding bearings with self-lubricating properties (such as plastic, graphite carbon bearings, etc.) are used in non lubricating liquid measurements; Superhard alloy bearings (such as tungsten carbide bearings) are used for easily vaporized fluids, fluids mixed with small particles, corrosive fluid measurements, and continuous use of transmitters.

Installation matters

Precautions for installation of turbine flowmeter:

Turbine flowmeter is an ideal instrument for measuring liquids. In order to ensure the accuracy of the flowmeter, installation specifications must be followed during use and installation, and the following points should be noted:

(1) Firstly, the selection of installation points for flow meters should not be affected by strong electromagnetic or mechanical vibrations. During welding and installation, welding slag and flange sealing gaskets must not protrude into the pipeline. The control valve of the flowmeter must be set as a fully open ball valve or gate valve to avoid affecting the flow state of the measured medium.

(2) There are various installation methods, including horizontal, inclined, and vertical installation. The flow characteristic curve may vary slightly depending on the installation method. In order to achieve higher measurement accuracy, please try to use horizontal installation as much as possible. However, if vertical installation is not allowed on site, it is necessary to recalibrate the turbine flowmeter and reset the instrument coefficient using vertical installation.

(3) As the running time increases or components are replaced, the instrument coefficient will change, so it is necessary to calibrate the flowmeter. Two aspects should be noted during verification: the fluid medium used for verification must be the same medium as the measured medium or a medium with similar viscosity.

Application scope

Explosion proof turbine flow meters are widely used in industrial fields such as petroleum, natural gas, chemical, pharmaceutical, food and beverage, mining, and metal processing that require high safety and reliability. It can be used to measure the flow rate of various media such as crude oil, natural gas, refined oil, chemicals, flammable liquids, and gases.